The digital divide and t-government in the United States: using the technology acceptance model to understand usage

This paper applies the technology acceptance model to explore the digital divide and transformational government (t-government) in the United States. Successful t-government is predicated on citizen adoption and usage of e-government services. The contribution of this research is to enhance our understanding of the factors associated with the usage of e-government services among members of a community on the unfortunate side of the divide. A questionnaire was administered to members, of a techno-disadvantaged public housing community and neighboring households, who partook in training or used the community computer lab. The results indicate that perceived access barriers and perceived ease of use (PEOU) are significantly associated with usage, while perceived usefulness (PU) is not. Among the demographic characteristics, educational level, employment status, and household income all have a significant impact on access barriers and employment is significantly associated with PEOU. Finally, PEOU is significantly related to PU. Overall, the results emphasize that t-government cannot cross the digital divide without accompanying employment programs and programs that enhance citizens’ ease in using such services.     

Micromachined scaffolds as primers for cartilage cell growth

Research on the growth and monitoring of cartilage cells in a controlled microstructured environment is important because of the consideration of how the microenvironment affects the cells involved in cartilage regeneration has been neglected to date. An experimental realisation has been demonstrated of biocompatible microstructured surfaces of controlled topography, which have been formed in biocompatible polyimide (Kapton) and in synthetic bioresorbable, epsiv-polycaprolactone (PCL). Bovine cartilage cell growth has been achieved in vitro on the microstructured surfaces and the retention of chondrocytic morphology has been investigated. The results demonstrate that PCL and Kapton microgrooved surfaces can act as primers for cartilage regeneration and repair in vitro or potentially in vivo, by retaining chondrocytic phenotype and enhancing cartilage formation     

Development of an automated process planning and production activity control system for the manufacturing of engineered work surfaces

This paper describes the design and implementation of an Automated Process Planning and Production Activity Control system for a make-to-order business and presents a formal methodology for the development of integrated manufacturing systems. The research is based on concepts developed in a project undertaken in a job shop Case Study facility, producing precision-engineered work surfaces. Industry today is facing numerous challenges on many fronts demanding improved availability and dissemination of processing information. On the demand side there is increased pressure on the manufacturer to meet deadlines and provide the customer with a prompt, efficient service, with accurate lead-time information, and a product of the utmost quality, on time. On the supply side there is increasing competition, variety in the market, a diverse product range, varying processing times and extremely short lead times. The nature of today's business world means that real-time information is a requirement and not an extra. This paper documents the design, structure and implementation of an Automated Process Planning system, which completely automates and integrates Order Entry stages from order receipt to order release. The developed system, namely the Manufacturing Optimization Information System, or MOIS, relays information to and from shop floor operators via a Production Activity Control system at each of the manufacturing stations. The MOIS is part of ongoing research endeavouring to integrate order processing, Process Planning and production control activities with a combined dynamic scheduling and material optimization module in a holistic manufacturing optimization system. The two specific aims of this paper are very clear; first, to bridge the theory-practice gap between theoretical concepts and real industrial issues surrounding Process Planning and Production Control. Secondly, to outline the design, structure and evolution of an integrated Automatic Process Planning and Production Activity Control system, installed in a make-to-order enterprise.     

Solubilisation of calcium and magnesium from the marine red algae Lithothamnion calcareum

Marine minerals are a potential source of calcium and magnesium for nutritional supplementation. This study analysed the solubilisation of calcium and magnesium from the skeletal remains of Lithothamnion calcareum. Scanning electron microscopy analysis demonstrated a nonporous microstructure. Spectrophotometric determination showed that the calcium and magnesium contents were 30.01 and 6.22% (w/w), respectively. Solubilisation of calcium and magnesium was highly pH dependent. The temperature‐dependent solubilisation of calcium fitted the shrinking core model. The apparent activation energy for calcium solubilisation was 28.6 kJ mol^?1. Inclusion of caseinophosphopeptides (CPPs), casein‐derived mineral binding peptides, during the solubilisation of calcium and magnesium appeared to decrease the extent of calcium solubilisation at pH 6.0 and 8.0. The results herein have implications for the choice of optimal pH conditions for the sustained release of calcium and magnesium from marine mineral sources.     

The influence of train properties on railway ground vibrations

This paper uses a sensitivity analysis to quantify the dominant train properties (mass and spacing of wheels and bogies) that contribute to ground-borne vibration generation, with the aim of reducing the complexity of train–track numerical models. This research is significant because ground-borne vibration from railways is a growing problem, particularly in urban areas. Despite this fact, attempting to predict vibration levels is complex because there are many variables that contribute to the overall dynamic response. Therefore, a deterministic approach is commonly used, that ignores many of these variables. Thus, this paper identifies the variables that can be ignored, while highlighting those that are highly influential on vibration generation. For this purpose, a previously validated 2.5D finite elements-boundary elements approach is used to simulate dynamic train–track interaction. It is computed many times for a variety of modelling variables to investigate the effect of each on the ground-borne vibration levels in the far field. It is found that increases in unsprung mass of the train causes a large increase in vibration levels. Furthermore, changes in wheel/bogie spacing and semi-sprung mass are found to have a minimal effect on vibration generation.     

Design of a composite sulfuric acid decomposition reactor,concentrator, and preheater for hydrogen generation processes

The Hybrid Sulfur Process, as well as similar sulfur cycles for the production of nuclear hydrogen, requires the decomposition of sulfuric acid into sulfur dioxide, oxygen, and water at temperatures above 800 °C and at pressures up to 9 MPa. The design of a reactor for this process presents numerous challenges in terms of maintaining small pressure differentials and utilizing currently available materials of construction. This paper focuses on design calculations for a composite reactor that preheats, concentrates, and decomposes sulfuric acid for use in the production of hydrogen. The decomposition reaction takes place within individual tubes of a multitube reactor.     

The effect of concentration of adsorbing solids on the partition coefficient

The results of a number of laboratory studies are presented to demonstrate an inverse relationship between concentration of adsorbing solids and partition coefficient. Various functional forms which define the relation are developed and correlated with the data. A power-law dependence of partition coefficient on concentration of solids is shown. The significance of this relationship in assessing the fate of hydrophobic pollutants in natural water systems is discussed.     

Alternating current electrical field effects on lettuce (Lactuca sativa) growing in hydroponic culture with and without cadmium contamination

The aim of the present study was to investigate the effect of a 10 Hz alternating current (10 Hz 1 V cm⁻¹) and a 50 Hz alternating current (50 Hz 1 V cm⁻¹) on the lettuce plant (Lactuca sativa) growing in a hydroponic (soil-free) culture. Thirty lettuce plants were pre-germinated, and then 15 of them were treated with cadmium solution (CdCl₂) of 5 mg/L in concentration. Ten plants (five plants with Cd and five plants without Cd) were subjected to a 10 Hz alternating current (AC) electrical field; 10 plants were subjected to a 50 Hz AC field. The rest of the plants were used as a control. The lettuce plants were harvested after a growth of 60 days. The chlorophyll content, biomass and metal content of the lettuce plants were determined. The biomass of the plants growing in non-contaminated medium was 28 and 106% higher under the 10 and the 50 Hz AC fields respectively compared to the control. Although the plant biomass was reduced by the presence of Cd in the growth medium, the biomass of the plants growing in Cd contaminated medium was 40 and 63% higher respectively for 10 and 50 Hz AC field compared to the plant growing in Cd contaminated medium without electrical treatment. Increased uptake of Cd in the plant shoot was found with the 50 Hz AC field. Significant accumulation and uptake of Cu in plant roots and shoots was found under both electrical treatments.     

Challenges in modelling the evolution of stress corrosion cracks from pits

The evolution of stress corrosion cracks from pits is important in many industrial applications but continues to be a challenge in both measurement and prediction. Life prediction in these circumstances has to account for pit growth kinetics, the conditions for the transition from pits to cracks, and the growth rate of cracks in the short and long crack domain. An example of importance is the performance of steam turbine rotors in power generation. Although stress corrosion failures are comparatively rare, the consequences can be severe and occasionally catastrophic. Consequently, considerable effort is being focused on evaluating the effect of operational variables on pitting and crack growth and in developing an improved basis for structural integrity assessment. A preliminary mathematical model based on deterministic equations with statistically variable input parameters was developed for simulating the evolution of the pit depth distribution at different exposure times, and the transformation to stress corrosion cracks was based on the Kondo criteria. The model predicted some features of the damage well but recent novel measurements of the evolution of stress corrosion cracks from pits combined with finite element analysis of the strain distribution suggest that the transition from a pit to a crack is more complex than can be accounted for by the Kondo approach.